1. Field of the Invention
The present invention relates to needles for use in medical procedures and, in particular, to safety shielded needles and needle assemblies for use in vaccination procedures.
2. Description of Related Art
Bifurcated or forked end needles are well-known for providing a simple and effective means for a doctor to administer a vaccine. During use, the bifurcated tip of the bifurcated needle is put into contact with either a dried or liquid substance, which adheres to the bifurcated needle tip. The bifurcated needle tip is then put into contact with the skin of the patient who is being administered the vaccination. The skin is either scratched or pierced with the needle tip so that the vaccination material may be absorbed into the skin of the patient. An alternative method of delivering the vaccination includes placing a drop of the vaccine onto the skin of the patient and contacting the skin of the patient with the bifurcated needle tip through the drop of vaccine. Alternatively, a standard pointed needle tip without a lumen may also be used when the drop of vaccine is applied directly to the skin of the patient.
The bifurcated needle is considered a significant medical advancement because it has allowed more people to be vaccinated with less serum. This has been especially important for those living in less developed areas because of the efficient and easy to use design, as well as the ease of replication.
Vaccination effectiveness, however, is reduced if the bifurcated needle is reused too many times. Moreover, reuse of such vaccination needles exposes patients to the risk of transmission of infectious diseases through percutaneous contact through the skin. Additionally, medical care workers using traditional vaccination needles are at an increased risk of exposure to infectious diseases due to the design of such needles, which makes them difficult to handle, as well as due to the repeated use of such needles.
In particular, bifurcated needles used to administer vaccinations are not traditionally sterilized or packaged in a single use container that would enable convenient storage and subsequent use. Additionally, such needles have traditionally been difficult to handle in that they typically do not include a hub attached to the opposite end of a needle from the tip, and do not typically include any sort of shield for protection from the needle prior to and after use.
For example, U.S. Pat. No. 3,194,237 to Rubin discloses a vaccination needle having a main shank with a pair of prongs at one end that define a slot of predetermined length, width and depth therebetween to hold an amount of liquid by capillary action. The shank of the needle is of sufficient length so that the non-prong end will function as a handle. U.S. Pat. No. 3,948,261 to Steiner discloses a reusable unit dose container for vaccines contained within a rigid receptacle, with a compressible closure for supporting a bifurcated needle bearing dried vaccine. The closure is adapted to support the needle in the container during a lyophilizing process while liquid vaccine is dried on the needle. The closure has grooves which permit the vaporized liquid from the vaccine to be withdrawn from the receptacle during lyophilizing, and can further seal the container.
Numerous devices have been developed in the medical field for shielding needles after use. Many of these devices are somewhat complex and costly. In addition, many of these devices are cumbersome to use in performing procedures. Furthermore, some of the devices are so specific that they preclude use of the device in certain procedures or with certain devices and/or assemblies.
For example, U.S. Pat. No. 5,188,611 discloses a reusable safety needle arrangement having a collar for engaging a needle and a slotted longitudinal shield which is attached to the collar at a hinge for pivoting over the needle. Such devices incorporating a pivoting shield assembly are typically used with hypodermic syringe needles or double-ended phlebotomy needles.
While shieldable syringes or needle assemblies are well known in the art for needles used to inject fluids and medicine into the circulatory system of the patient (i.e., venipuncture) such shielding has not previously been used in connection with vaccination needles such as bifurcated needles. In view of the foregoing, a need exists for a shieldable needle assembly for use with a unit dose vaccination needle that is easily manufactured, that is simple to use, that is easily sterilized and maintained in a sterile condition until used, that can be safely disposed of, and that does not interfere with normal practices of bifurcated needle use.